1. Product Overview
The VEMER AST2 VE343000 is an advanced digital astronomical timer designed for precise control of lighting systems. It automatically manages switching operations between sunset and sunrise, adapting to your specific geographical location. This makes it an ideal solution for shop window lighting, illuminated signs, and other applications requiring automatic twilight-dependent control.

Figure 1: Front view of the VEMER AST2 VE343000 Digital Astronomical Timer.
Key Features:
- Astronomical time switch with night programming capabilities.
- Automatic programming: Switches 'On' at sunset and 'Off' at sunrise.
- Flexible programming options: Manual configuration via keypad or automatic setup using the NFC interface.
- Integrated backup battery ensures settings are retained during power outages.
- Free dedicated app available for smartphones and tablets for convenient programming.
- Backlit LCD screen displays current date, time, and relay status for easy monitoring.
- Power supply: 230V.
2. Installation and Initial Setup
2.1 Mounting
The VEMER AST2 VE343000 is designed for DIN rail mounting. Ensure the device is securely clipped onto a standard DIN rail within an electrical enclosure. Proper ventilation should be maintained around the device.
2.2 Power Connection
Connect the timer to a 230V power supply using the screw terminals provided. Ensure all connections are secure and comply with local electrical safety regulations. It is recommended that installation be performed by a qualified electrician.
2.3 Initial Configuration
Upon initial power-up, the device may require basic time and location settings. These can be configured manually using the device's keypad or more conveniently via the NFC app on a smartphone or tablet. Refer to the 'Operation and Programming' section for detailed instructions.
3. Operation and Programming
3.1 Astronomical Function
The primary function of the AST2 VE343000 is its astronomical programming. Once your geographical location is set, the timer automatically calculates sunset and sunrise times daily, adjusting for seasonal changes. This allows for precise 'On at sunset - Off at sunrise' control without manual adjustments.
3.2 Manual Programming
The device can be programmed directly using the buttons on its front panel. The backlit LCD screen guides you through setting the date, time, and specific switching programs. Consult the detailed German instruction manual for step-by-step manual programming procedures.

Figure 2: Examples of programming diagrams for the timer, illustrating various ON/OFF cycles relative to sunset and sunrise.
3.3 NFC App Programming
For ease of use, download the free VEMER memo app to your smartphone or tablet. The device's NFC interface allows you to create, transfer, and acquire programs directly from your mobile device. This method simplifies complex programming tasks and allows for quick adjustments.

Figure 3: The VEMER memo app interface on a smartphone, showing options for program creation and settings.
3.4 Key Lock Function
The timer includes a password-protected 'key lock' function. This feature is particularly useful in public installations to prevent unauthorized personnel from making changes to the programmed settings. Activate this function through the device menu or the NFC app.
4. Maintenance
4.1 Backup Battery Replacement
The VEMER AST2 VE343000 is equipped with a backup battery to preserve settings during power interruptions. If the display shows a low battery indicator or settings are lost after a power outage, the backup battery may need replacement. The battery compartment is accessible by removing the device cover.

Figure 4: Rear view of the timer, highlighting the accessible backup battery compartment.
To replace the battery:
- Ensure the device is disconnected from the main power supply.
- Carefully remove the device cover to access the battery compartment.
- Replace the old battery with a new, compatible backup battery (e.g., CR2032, as indicated on the battery itself).
- Securely reattach the device cover.
- Reconnect the device to the power supply.
5. Troubleshooting
If you encounter issues with your VEMER AST2 VE343000, consider the following general troubleshooting steps:
- No Display/Power: Check the main power supply to the device. Ensure all wiring connections are secure.
- Incorrect Switching Times: Verify that the geographical location and current time are correctly set. Ensure the astronomical function is enabled if desired.
- Settings Not Retained: The backup battery may be depleted. Refer to Section 4.1 for replacement instructions.
- App Connectivity Issues: Ensure NFC is enabled on your smartphone/tablet and that the device is placed correctly for NFC communication.
- Unauthorized Changes: If settings are being altered without permission, ensure the 'key lock' function is activated and secured with a strong password.
For more detailed troubleshooting or specific error codes, please refer to the comprehensive instruction manual provided with the product, which is available in German.
6. Technical Specifications
| Specification | Value |
|---|---|
| Brand | VEMER |
| Model Number | VE343000 |
| Product Type Name | Digital Timer with Astronomical Programming, DIN Rail Mount, Two Channels |
| Operating Mode | Automatic |
| Power Supply | 230V |
| Circuit Type | 2-way |
| Mounting Type | DIN Rail Mount |
| Control Method | Via App / Manual |
| Communication Protocol | NFC |
| Display | Backlit LCD |
| Connection Type | Normally Open |
| Connector Type | Clamp |
| Switch Type | TRIAC |
| Terminal | Screw |
| Material | Kunststof (Plastic) |
| Contact Material | Copper |
| Color | White |
| Item Dimensions (LxWxH) | 36 x 65 x 90 mm |
| Item Weight | 150 grams |
| Compliance | CE, RoHS |
| GTIN | 08007951121312 |
7. Warranty and Support
For warranty information, technical support, or service inquiries, please contact VEMER customer service or your authorized dealer. Detailed contact information can typically be found on the manufacturer's official website or within the product packaging.
Please note that the comprehensive instruction manual is available in German. It contains detailed information on installation, programming, and advanced features not covered in this summary. Always refer to the official manual for complete and up-to-date information.





